Breech-loading mortar with obturator case



June 21, 1949. s, w ss 2,473,555

BREECH-LOADING MORTAR WITH OBTURATOR CASE Filed July 24, 1947 3 Sheets-Sheet 1 77 6 8 Saul Weiss Hot/H4415 June 21, 1949. 5, wg ss 2,473,555

BREECH-LOADING MORTAR WITH OBTURATOR CASE Filed July 24, 1947 a sheets-she t 3 45 a f a5 94 a9 JIM l m 1| m 7/ mm Ill Patented June 21, 1949 UNI TED TATES TENT OFFICE BREEC'H-LOADING YMORTAR WIT-H BTURATOR- CASE :Saul -Weiss, Washington, 0. assignor "to the .United States of America as represented by the Secretary of War ftGran'ted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) 11 .Claims.

1hav.e1 obturatingnmeansifor sealing the breech to preventsescapeof ,the gases vof the propellant of 'lthe ;mortar round. The particularly .novel and -useful-h featuressofrtheimproved mortar are the i obturatingmeans .andthermountingmeans therefor. .These, features ocmprisean .o'bturator .case, ea .breechblo'ck and a breech ring which are .so .hesigned that-theround is mounted in the case which isattached .to thebiock. The round is .chambered sand .the breech .is .closed and sealed .bythesingle operation of seating the block in thering. .The;b1ock.is provided .with improved Jfirinemans and vtrigger .means .Ior operating "thefiringnneans. 'Sincethe round is mounted .in the case on lthelblockaprior toseatingof the .Jolockin .the ring,.and.hence ..prior to .chambering the round, thejtrigger. means hasasaiety latch preventing aactuation of ,the .trigger .before the 1 round is. chambered.

released .to ..allow operation of the trigger ,when .the'block isseated and .themound chambered. The trigger means also has .a latch-to engage {athe block ,to Iinsure..seal-ing of the .breech Lon firing. "The structure Lis;su'ch that the .mortar f canv not be..fire'di..un1ess .the vblock .is .disposed v.to seal the breech, and .when it is so disposed and the trigger'fires the. mortaritslatch retains the block .to. maintain J the ..;seal.

"While there has. .been .i11ustrated in the draw- -ingsnand hereinafter folly described oneaspecific embodimentoiuthe. invention, it is .to-berdistindtiy .understood zthat. the invent-remis not considered to be .iimiteld to. said aspecific embodiment, and

llhislatch is.automatica11y tthat;itszscopezis;definedsby .theqrclaims ap ended iahereto.

itheidrawings Fig. 1 is a side elevation offthei; improved mortar aand section of the amount, parts 'of the barrel randrmount bei-ng -broken --'awa;y

Fig. 2 'is' a 'rear endelevation;

-Figf3'is a fragmentary'"bottom plan *Eig. 4." E a-vertical: section onfithe j1 ine:4. 4 ,of

.eFig. 2;:in-the 'fdireetiqn of" the arrows;

i 5 is 'i sm n iew sim la .to .Fi showin t trig e and bolt i cook ng qs tion;

Fig. 6 is a View similar to Fig. 5, showing the tri e return ng o normal osit on .Fig. '1 is a ve ti a section on th l ne 1-4 of Fig. 6, in the direetio o thea rows;

Fig. 8 is a lon itudinelniiht v r iea se tion .o the breech rin th .breeehhl k an bar e rem ved;

Fi .9 is a sid el va pa t i seeti naa parts br e away o the hreechbloc r move f om the b ee h r ng the ea e mount on th 'block and a projectilegno ntedtherein;

i 0 s a ea -file a ion .s mi1a .iofi showi g theh eech. ....,..se. .te inimthebrew ring, and bef re .5 been rotated o s a i the rin gis a bro e p an simi a to Fi v.3 showing the pa they a dispos d .inlliig- .As illustrated n the drawin s th improved mortar has a breeohring J provided .Withsu itble exterior thr ads 2 meshin w t thr ad 3 o .a.suita.b1.e .moun .4 a the Wal .Q a an for.exampl uandi term t r ad i r ts a t o po m s ng with e te io th ead .6 .01 a barrel 7 seatedin s ch portion, itsrearendbearing on an interior pe 'pheral flange a ofring The ring I is rovided i poster p o with interrupted threads .3 meshing with interrupted threads [0 von a hreechblock ,H. .The breechblock H has a leducedportion 12 on which is threaded a sleeve [,3 of an ,obturator case .14 seated in thehreechring 1 between breechbloek -H and'barrel "I. It will be noted that tapered interior and exterior ,surfaces 15 and [6 are p dcdfo r na an pase fliwresn ctivelybto effect a gas-tight joint when the case L4 is .seated an'd that the fQIZ-W fdfind I] ofpase I4 :is slightl yposterior jiange 1B. The case .M has an axial opening I18 .its rear ail .19 and a concentric socket 20 f rvvardly of opening 18. A us ns'fl' eates inppenin It :Wi a n .r ph ange 3 s ate in socke 32 an r h ded nt .t ed1 or i J o lq 1 I. Th b hinezlha lidab vm lm e therr- .i afirine piniig vided wi heflang Z1 1 lid- -a b1e;in a1 borej in bushing fl, andva fr ust,o- ;co nical head 26 intruded into a frusto-conical socket 21 in h n 2 Th reduced fo wa portion 28 of the pin .2 3 s1idab1e in bore ZLof ,bushing 2| is intrndeddnt an axial socketfifl in he wardiacefil o rlqy i g 2 I. Th bushing :2 .has ooke ,3; immed te i h re of and c ncen ric with or .Z fi QWh-E i Seat a stop washer 33 about pin 23 and provided on its front face with a seating ring 33a bearing on flange 2 when pin 23 is retracted. The bushing iii has a socket t l immediately to the rear of and concentric with the socket 32, in which is seated a stop ring 35 about and spaced radially from pin 23. The pin 23 has a peripheral groove in which is seated a lock ring 31, comprising two portions, and slidable in ring 35. A coil spring 38 about pin 23 is confined between washer 33 and ring 3?. The rear end 39 of pin 23 protrudes from the rear edge of ring 35 into a bore (it, in the breechlock ii, having a reduced portion M at the rear face 52 of block ii, to form a peripheral shoulder 4-3. Slidable in reduced portion M is a bolt 44 having on its forward end an enlarged portion 65 received in a stop collar #38 slidable in the bore ii]. The collar MS has an inwardly turned flange M on its rear end to engage the peripheral shoulder formed by enlarged portion 45. A coil spring til about bolt M is confined between shoulder 43 and flange 41 to bias bolt M forwardly. It will be noted (Fig. 4) that rear end 39, of pin 23 biased rearwardly by spring 38, normally bears against the front end of enlarged portion 45 of bolt M to press shoulder 18 against flange t? and against spring 49 to maintain bolt M in normal position. When so disposed, the bolt 34 extends rearward beyond the rear face 42 of block I5, and has a stem 50 projecting rearwardly and having a head having a cylindrical periphery 52 and a circumferential bevel 53 on its rear face 54.

The portions of the breechblock i I above mentioned, viz. the portion provided with threads I!) and the reduced portion l2, are cylindrical to conform to the cylindrical interior of the breech ring i. The block I! has a rear portion 55 having parallelly disposed plane sides and convex top and bottom ends. Projecting rearwardly from the lower end of portion 55 there is a pair of lugs 56 in which is pivoted a trigger 51. The trigger 5'5 is provided on its forward end with a slot 53 forming lateral walls 59 in which is pivoted a finger at having a tail 6| pressed into engagement with the bottom 62 of slot 58 by a plunger 63 slidable in socket is in trigger 57 and biased against finger 66 by spring 65. The lower end of the trigger 5? is bifurcated to form legs 65 and 57 between which there is pivoted a safety latch 58 L-shaped to provide an operating finger G9 and a bifurcated head it. An operating spring a! is coiled about pintle 72 of latch 68 and has its loop end 73 received in head 70 and it free ends M bearing on surface '55 of trigger 5'! between legs 66 and 61. Trigger 557 is cut away to provide a surface 76 intermediate bottom 52 of slot 58 and surface 715 (Fig. 9). Leg ti projects downwardly to form a locking slide l? having an arcuate edge '58 concentric with the pivot pin 79 of trigger 5?. Trigger 51 has a handle 85. The breech ring I has a portion 8% projecting rearwardly from its portion having the interrupted threads 9 (see Figures 8 and The portion 8! is cut away at the upper side of ring 6 to form an arcuate recess 82 defined at its right end, as viewed in Figs. 1 and 2, by a shoulder 83 having a plane face 8 Portion 8i is cut away at the lower side of ring I to form an arcuate recess 85 defined at its left end, as viewed in Figs. 3 and 10, by shoulder 86 having a plane face 81. The faces 84 and 8'! lie in parallel planes symmetrically disposed on opposite sides of the longitudinal axis of ring I. The recess 85 has, at its right end as viewed in Figs. 3 and 10, a cam surface t8 sloping rearwardly to the rear edge of portion 8i. Spaced to the right (Fig. 10) of cam 88 there is a rearwardl projecting lug 89 on the rear edge of portion and to the right of lug 83 there is a shallow slot til on the rear edge of portion 8i. it will be noted (Figs. 2 and 8) that the breech ring 5 has a lug 9! on the inner surface of ring I in one of the interruptions of the threads 9 registering with threads 9.

The breechblock H has in its bottom at the rear end a recess 92 to receive the head 1|] of the safety latch 63, and is provided with an op erating handle 83 mounted in the top of portion 55.

It will be noted (Figs. 4 and 9) that the forward surface of wall l9 of the case M and the front end of the bushing H are configured to receive the rear ends 93 of the fins 95 of a projectile 96 about the bushing 21!, the primer 9! of the propellant cartridge 98 being seated on the face of the bushing 25. The projectile 9S retained in the case I l by a resilient split ring 5'9 in a peripheral groove i551 in case M which yieldingly engages the fins 95 being seated against shoulders Elli on the fins 95 rearward of ring The assembling of the parts will now be explained. The barrel 1 is threaded into the breech ring I which is threaded into the mount The breechblock H with operating handle 93 mounted therein is then equipped with bolt i l and firing mechanism, trigger 5! and its associated mechanism, and the obturator case M. It will be noted (Fig, 4) that the belt 3 3 and its head 55 are co-axial and of the same diameter, fitting nicely through reduced portion 4| of bore til in breechblock H. These parts are assembled by passing head 5i and bolt 44 through the collar it until its flange 41 seats against shoulder 58 of enlarged portion d5 of bolt 54. The spring :39 is placed about bolt Ml, its forward end seating against collar 35. The parts are then mounted in the breechblock i! by passing them rearwardly through bore iii, the rear end of bolt 4, its stem 55 and head 5i passing through reduced portion M, the rear end of spring id seating on shoulder 43, and collar 46 being positioned at the forward end of bore w. The firing mechanism, associated with bolt 36, is assembled and mounted in breechbloci: H as follows. The washer 33 is placed on firing pin 23 against flange 24. The spring 33 is placed about pin 23 and the two portions of ring 3'1 are seated in groove 35 in pin 23 to confine spring 38 between washer 33 and ring 31'. The parts thus assembled are then inserted forwardly into the bushing 2|. The stop ring is passed over ring 31 and spring 38 to seat in socket 35 of the bushing 2|. The firing mechanism is now assembled preparatory to installation in breechblock ll, before which the obturator case it must be mounted on breechblock l l. The sleeve 13 of the case M is threaded on the reduced portion I2 of block H. The bushing 21 is then threaded into reduced portion l2 and seated in opening it and socket 20 in wall E9 of the case M, the assembled parts being disposed as shown in Fig. 4.

The trigger 51 and its associated mechanism are assembled before mounting on the breechblock H. The spring 65 and plunger 63 are mounted in socket 64 in the trigger 5?, and finger 60 is pivoted on walk 59 and in slot 58. Safety latch 68 is then mounted in the bifurcated lower end of the trigger 57, its bifurcated head 10 proamma iiieetlng "upwardly *and its operating finger 59 iprojecting forwardly; thespring It being received itabout' pintle "12 and its ends-13*arrd 14 bearing Tagainst head *7 Iland surf-ace I 5 of the *tri'gger t'a'l.

"g'lhe assernbled -parts--'-are"then mountedon the "breechblock *I'l. by -pivoting trigger- 5? on pintle 19 in lugs-"iitinportion 55* of breechbloek- I- I It willbemoted 'GFigx 9) *that-when the-trigger i 5'l'z has"been mounted on-*the'breechbloch II pas 6 ascribed gas ti'ght sealvzof ease I 4. Alsoit zlseritaizeid that slide T1 cannot rise -'-untilblock II -is'Fful'ly rotated to seal case M; thus*-preventing functioning of trigger 51 to' iire-the *projectileLQG ifthe case 1 I4 is not properly se'aled. To fire the projectile 96, the trigger 51 is rocked by *pixllingi its handle tmrearwardly,"causingfinger'tIl to engage -head 5 I of==bolt flyretracting bolt M, compressing sspring lii; untilrotation of trigger fi'l moves finger bove describedf-the'parts are so 'relatively disfifit downwardly :omof -head 5l "(Fig.i5) ist iover the -rear ends 94 and engage against-a'shoul- 4 E' 25headi'5I' (Fig. 7).

Hers I I! I on ?fins 95. -W hen the proj'ectile- SB :is so amounted inpase M iihaprimef I is seated against tithe face 3'! of the bu'Shing ZI concentric with socketifi0 andiforwardiportion 2 8- of firing pinF2-3. .Actuation of the firing pin 2 3 tofifirethe -primer 5391::is effectually'prevented by the safety latch 68, has .aabove adescr-ibed, szafter t'he 'rprojectile 96 has I-cbeenemountedoandfibefore the? breechblock I I fhas :iiheeniseatedrin:breeclr ring l tWhenwthetprojectilefifi? is ttot be fi 'd lfmmffthe miortar, ;t'he i-comp'lete @nnitmassemble'd as above 'z-idescribedzandmomprising the .breechblock I I case 1. M and: projectile 595 is inserted forwardly' into ring 'iIno ider.ato register-the: threads: III onblock I I 'IMibhflJhGffi'fl-CEI'WDMOHS ofxthreads 91in ring Irand :rperm'iti, axialcdisplacement zofkblo'cki i I, the! block 9 I I "isrnot'ate'd zclockwise (FigflO) to 'dispose handle -i93 against: surface 84: and; legrrfifi nof ztriggerfl51 sagainstsurface 81 The;above izdescnihed 'unititis misplaced;axiallyuntilthe forward 'edgeoftthreads 5:1 0 r bear eagainst lug 9 I win rthe Erinterruption rsof threads 9 in ring I, therebycregistei'ingzthreads 9liandllil. .The block II is then rotated countercl'o ckwisdby its handle 93, moving from its position of Fig. L0=-to1its position-JofeEig. 2, and effecting the following results. Meshing threads 9 and -I 0 cause further axiab'displacementof' block I I relative to ring I. The operative finger $9 of the safety latcl'infifl-iseintruded intorrecesssii 5 in portion SI of ring I and is cammed downwardly by cam o surface 88 so that its forward end is engaged *b'elow the-portion" 8 I of-ring I therebyidisposing -"-la'tch 68;;as shown inFig.-'4,"tensioning:spring II to bias t'riggerfilagainst p'or'tion 55 of'block I I. In thismo'sition, "latch--68 is disposed' to-'release ri er swor firing. Itw'ill-benoted that trigger 5 5? is not released until block I I -is; roper,1y:seated *r lnring I Due-t0 the -corresponding-ly tapered interior surface l5 of ring I and exterior surface I6 of case It, the axial displacement by action of threads 9 and I9 causes case I4 to spiral into a gas-tight sealed seating in ring I.

When the block I I and case I4' are disposed, as above described, the trigger 51 is conditioned for firing the projectile 98. It will be noted (Figs. 1 and 3) that the locking slide TI on the lower end of leg 6'! of the trigger 51 is so disposed that when the trigger 51 is rocked to fire the projectile 16, the slide H can rise along the lug 89 and into the slot 90, thereby locking the block II against releasingzbolt A lavhich isprojected forwardlyby expanding springi49. While collar fi i'fi stops -at t'the forward endzdfi bore flfl, strikingastop'ring ifl, t thenbolt M smovesiby rinertia through collar 46 to -5- impact pin 23 compressing'its spring 38 r-an'd' in- :trudimg its tipfiztalintoetheprimer '9'Iffiring 'the mojectiie 9B.

e-Rockingszof the triggert51 to fire theprojectiie T196 Fh'gzfi) tensionsxspring l I. of safety latche68 .1 swhichmeturns triggers?! to normal position when :I'l'av-ingdescribed the :invention; I claim:

1. o; In a mortar, ithercombination: ofaa" breech :rinschawing an anterior ,=harrelrreceiving.portion, I331 :DOS'IJGIJEOI'Z breech-i: blockrreceiving ,po'rtionandzan gg -intermedia-tei taperedsportion; aabarrelsemounted said-anteriorportion gzarbreechblockr removably 1mountedjn:lsaidrposterior rportion; and: an cobturator case mounted on said blockmhaving xa staperedxexteriorzsurfaceaandiseatediinsaidxinterammediateportion.

.2. In a 'm-ortar, 1 the "combination :of :a .pbreech xr1-ng -having -cylindrical -portion :provided iwith Anterior interrupted threadsgand: a taperedt.:por- -tion -;provided with a smooth interior surfacepza 4oizbarrelsmounted insaidri'ng; a breechblock having 1 amylindricalportion: provided with exterior-interruptedz threads; and ;an=--obturator-case.- mounted on said: :block, having. :a': tapered smooth -exterior surfaee andsseated sin-said taperedz-portionwhen fisthering; and-.zbloeh threadsmesh.

a 3.,sInaa-amortar, the combination, ofia'ibllefich 5 ring havingamantermr:barrel receivingpportion, 5,3,; posterior-1 breechblockereceiving portionandzaan intermediate tapered- ;portion; :a :barrel mounted sin said ant.eriorg.:portion; a breechblock -rem-ov- -.-.detachably mounting :al'lprojectile in isaid-a-case;

sand rmeanssin-isaideblock and-:said'case for: firing osaid projectile from: theanortar.

'44.. In a.-.--mortar, ithe combination of :a'breech ringthaving) interior threads-and amortionzrhavting lam-smooth; *mterior surface tapering: inwardly lv-ilonwardly aasbreechbloak threadedon;theathreads of said ring; and an obturator casex-mountedmn esaidnblo-ck. andldiavin -ia SmOOthPBXIIeIiOfiSUi'faCG tapering inwardly forwardly, said case being seated in said portion of said ring, and said tapered surfaces being juxtaposed to effect a gastight joint between said ring and said case by the clamping effect produced by the threaded engagement of said ring and block when the block and case are mounted in said ring.

5. In a mortar, the combination of a breech ring having interior threads at its forward and rear ends and a portion intermediate the forclockwise rotation to maintain the above deward and rear threads having a smooth interior surface tapering inwardly forwardly; a barrel threaded on the forward threads of said ring; a breechblock threaded on the rear threads of said ring; an obturator case mounted on said block and having a smooth exterior surface tapering inwardly forwardly; and means in said case for mounting a projectile in said case, said case being seated in said intermediate portion of said ring, said projectile being chambered in said barrel, and said tapered surfaces being juxtaposed to efiect a gas-tight joint between said ring and said case by the clamping effect produced by the threaded engagement of said ring and block when the block and case are mounted in said ring.

6. In a mortar, the combination of a breech ring; a barrel mounted in said ring; a breechblock mountable in said ring and having means for so mounting a primed mortar round on said block that the round is chambered in said barrel when the block is mounted in said ring; firing means in said block including a striker disposed closely adjacent the primer of the round when the round is mounted in the block; a trigger pivoted on said block for operating said striker to impact the primer to fire the round; and a safety latch pivoted on said trigger and engaging said block to immobilize the trigger on the block to prevent firing of the round before the block is mounted in said ring, said latch being engaged by said ring and releasing the trigger when the block is so mounted in the ring as to chamber the round.

'7. In a mortar, the combination of a block provided with means for mounting the block in the breech of the mortar; means mounted on said block for sealing the breech when the block is so mounted; means, in said sealing means, for mounting a mortar round on said block and chambering said round when the block is mounted; means in said block and said sealing means for firing said round, the round being in position for firin relative to said firing means when it is mounted in said sealing means; and safety means for immobilizing said firing means so long as the block, sealing means and round are unmounted, said safety means being inoperative when the block and sealing means are mounted and the round is chambered.

8. In a mortar, the combination of a block provided with means for removably mounting the block in the breech of the mortar; means in said block for firing a round in the mortar; a trigger for operating said firing means pivoted on said block; and a safety latch pivoted on said trigger and comprising a head biased to engage said block to immobilize said trigger when said block is removed from the mortar, and an operating finger connected to said head, engaging the mortar breech when said block is mounted therein, and disengaging said head from said block to release said trigger.

9. In a mortar, the combination of a breech ring; a breechblock removably mounted therein; firing means in said block; a manually operated trigger for said means pivoted on said block; a pintle pin on said trigger; a safety latch pivoted on said pin and comprising a head engaging said block to immobilize said trigger when said block is removed from said ring, and an operating finger connected to said head engaging said ring when said block is mounted in said ring to disengage said head from said block to release said trigger; and coil spring on said pin and having two ends resiliently engaging said trigger and said latch, respectively, and biasing said latch to engage said head with said block and said finger with said ring, and biasing said trigger to normal position for manual operation for firing.

10. In a mortar, the combination of a breech ring having interior threads and an exterior notch; a breechblock threaded on the threads of said ring; an obturator case mounted on said block, said case being seated in said ring to efiect a gas-tight joint between said ring and said case by the clamping effect produced by the threaded engagement of said ring and block when the block and case are mounted in said ring; and a latch pivoted on said block for locking said block to said ring, said latch being moved by said block into position to be swung into said notch when said case is seated.

11. In a mortar, the combination of a breech ring having interior threads and an exterior notch; a breechblock threaded on the threads of said ring; an obturator case mounted on said block, said case being seated in said ring to effect a gas-tight joint between said ring and said case by the clamping effect produced by the threaded engagement of said ring and block when the block and case are mounted in said ring; firing means in said block and case; a trigger for said firing means pivoted on said block; a latch on said trigger for locking said block to said ring, said latch being moved by said block into position to permit said trigger to be swung to move said latch into said notch, when said case is seated, and said trigger being inoperative until said latch is so moved.

SAUL WEISS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 466,320 Benet Jan. 5, 1892 474,289 Canet May 3, 1892 483,267 Seabury Sept. 27, 1892 2,072,608 Smith Mar. 2, 1937 2,245,621 Summerbell June 17, 1941 2,245,623 Summerbell June 17, 1941 2,399,248 Patrick et a1 Apr. 30, 1946 

